Cooling unit for refrigerating machines



Dec. 25, 1934. L. s. CHADWICK El AL 1,985,816

\ COOLING UNIT FOR REFRIGERATING MACHINES Filed April 20, 1935 4 Sheets-Sheet 1 Dec. 25, 1934. L. s. CHADWICK ET AL 1,985,316

I COOLING UNIT FOR REFRIGERATING MACHINES Filed April 20, 1935' 4 Sheets-Sheet 3 L-Iu I I I I I l l I I I Dec. 25, 1934. L. s. CHADWICK ET AL 1,985,316

COOLING UNIT FOR REFRIGERATING MACHINES Filed April 20, 1955 4 Sheets-Sheet 4 Patented Dec. 2 5, 1934 PATENT OFFICE COOLING UNIT FOR REFRIGERATING MACHINES Lee S. Chadwick, Shaker Heights Village, and Marc Resek and Theodore B. Focke, Cleveland Heights, Ohio, assignors to Perfection Stove Company, Cleveland, Ohio Ohio, a corporation of Application April 20, 1933, Serial No. 667,014

15 Claims.

This invention has to do with improvements in and relating to the evaporator or cooling unit of artificial refrigeration apparatus or machines.

The class of evaporator to which the invention especially pertains is that having associated with it a brine tank or the like for stabilizing the temperature of the refrigeration or food compartment and freezing space, it being well understood that in refrigeration apparatus or machines, the temperature of the evaporator rises during certain phases in the cycle'of operation, as during the heating-condensing period of each cycle of operation of refrigerating machines of the intermittent absorption type; and unless a suitable holdover means is provided, this rise in temperature causes ice in the freezing space to melt and the food compartment to warm up to an undesirable degree. I

Among the more general objects of our invention are the provision of'a, very efficient, strong and durable evaporator that is relatively simple of construction and economical of manufacture, the same being, desirably, in the nature of a shelf or support for one or more ice trays; and the combination, with such an evaporator, of a tank or receptacle containing a suitable brine or 1 other cold storage substance having a stabilizing effect on the temperature of the surrounding atmosphere, said tank or receptacle being preferably removable, for one reason, to facilitate cleaning.

To promote sanitation as well as for the sake of appearance it is customary to coat the parts of thecoolingunit that are susceptible to such treatment with a vitreous enamel or like material, and such coating, as is well known, is fragile and therefore chips easily and is readily fractured by distortion or expansion of the surface to which it is applied:

More specific objects of our invention are to provide a brine tank or receptacle for use with the'evaporator of refrigeration apparatus or machines that makes use of the latent heat of fusion of a congealing, substance; which tank or receptacle is desirably coated with vitreous enamel or the like and, to avoid distortion or expansion, contains a non-eutectic solution that will not freeze into a solid mass 'within the possible temperature range of the apparatus; to provide a tank or receptacle of the aforesaid nature that is so constructed, and is supplied with solution in such quantity, that a space within the tank or receptacle is provided for the expansion of the solution as it tends to solidify, and such space maintained substantially uniform through ut th entire top portion of the receptacle to the end that strains or stresses will not be so concentrated within limited areas as to cause distortion of the vessel or expansion of the surface thereof with consequential cracking of the enamel; and to provide a tank or receptacle that cooperates with the evaporator in such manner as to render its attachment'to and removal from the same especially convenient. In this connection it may be pointed out that a further purpose in making the tank or receptacle removable is that of enabling the same to be readily replaced, should it become damaged through any cause, without having to dismantle or disturb any of the other parts of the apparatus.

The foregoing objects, with others hereinafter appearing, are obtained in the embodiment of the invention illustrated in the accompanying drawings wherein Fig. 1 is a fragmentary sectional side elevation of an intermittent absorption refrigerating machine incorporating our improved cooling unit; Fig. 2 is a partial front elevation of the cooling unit on a scale somewhat enlarged over that of Fig. 1, all following views being on the larger scale; Fig. 3 is a central, vertical, longitudinal section through the cooling unit and the parts of the machine thereabove; Fig. 4 is a transverse section on the line 4-4 of Fig. 3; Fig; 5 is a top plan view and Fig. 6 a bottom plan view of the evaporator, proper, parts being broken away to better reveal the construction; Fig. 7 is a central vertical longitudinal section through the evaporator; Fig. 8 is a transverse section on the line 8-8 of Fig. 5; Fig. 9 is a top plan view of the brine tank or receptacle removed from the evaporator; Fig. 10 is a central vertical longitudinal section through the 0 same; and Fig. 11 is a transverse section on the line 11-11 of Fig. 9.

- In Fig. 1, the body portion of the cabinet of the refrigerating apparatus or machine is designated 1' and consists of the usual lagged or insulated walls surrounding the refrigeration or food compartment 2 that is closed at the front by a door 3. Applied to the upper end of the body portion 1 is a top 4 that incorporates a base frame 5, from which is supported, by'brackets 6, a receiver 7 that is shown in the'form of a. cylindrical tank As previously stated, the machine illustrated in part in Fig. 1 is of the intermittent absorption type and leading from the top rear portion. of

the receiver is a conduit 11 which returns the refrigerant gas to the generator-absorber end of the system (not shown) during the cooling-evaporating period of a cycle of operation. The space surrounding the receiver 7 within the shell 8 and top 4 is filled with a suitable insulating material 12.

Welded at 15 to the lower end of the connection 10 of the receiver is the'rim of 'a cup or disa liquid anhydrous refrigerant, the same standingtributing head 16 that forms a part of the evaporator and is, in effect, a continuation of the connection 10. Extending laterally. and forwardly from the lower portion of the cup or distributing head 16 are loops 1'7 of tubing (Figs. 5. to 8), it being apparent especially from Fig. '7 that each loop communicates with one side of the cup 16 near the bottom thereof and extends laterally and thence forwardly therefrom, gradually rising as it progresses .and then returns on a continued upward incline to where it again joins the forward side of the cup at an elevation appreciably above the former end. The loops 1'! and the bottom portion of the cup 16 are encased within a casting of zinc, aluminum or other suitable metal which will be referred to hereinafter as the body 18. ,This body is preferably in the nature of a shelf, being flat on top and having a transverse rib 20 atits forward end whose front surface is inclined upwardly and forwardly and having, at its opposite end, a boss 22 that surrounds the lower portion of the cup 16 and incorporates at its rear a depending stop 23. On its underneath surface, the body 18 has ribs 24 that encase the loops 17 (Fig. 8).

A sleeve 25 is interposed between. a shoulder of the aforesaid boss 9 and an opposed part of the evaporator body 18 and surrounds the adjacent ends of theconnection 10 and cup 16, the sleeve being held in place by the reduced lower end of said boss that fits snugly within the same, and being filledwith suitable insulation.

Without going into the details of the refrigerating apparatus or machine, it may be explained briefly that refrigerant condensate is delivered to the receiver and evaporator during the heating condensing period of a cycle of operation through a conduit 27 (Fig. 3), and during the early stage of such period, any absorbent condensate that is present in the evaporator is returned to the generator-absorber end of the system through a liquid return tube 28. For a full disclosure of the construction and operation of an intermittent abwithin the receiver to a level near the top thereof, and during thecooling-evaporating period, this refrigerant gradually gasifles and returns through the conduit 11 to be re-absorbed by the weak solution in the generator-absorber end of the system, during which time heat is abstracted from the atmosphere of the refrigeration or food compartment 2, lowering the temperature of said compartment sumciently to preserve foodstuffs placed therein. The temperature in the immediate vicinity of the evaporator drops below f reezing so that water within one or more trays 30 (Fig. 1) that is or are placed upon the shelf-like body 18 of the evaporator freezes solid. At this point it may be explained that, due to the inclination of the loops 17, the refrigerant is caused to circulate through the loops, thus increasing the efliciency of the evaporator.

To protect the ice within the freezing space above the evaporator against melting, and also to better stabilize the temperature of the refrigeration or food compartment 2, during the heating-condensing period when relatively warm liquid refrigerant is collecting in the evaporator and receiver, the evaporator has associated with it a tank or receptacle 33 which contains a cold storage substance or solution-34 to about the level shown in Fig. 4. :This tank or receptacle is an elongated vessel whose body portion 35 extends beneath and laterally beyond the body 18 of the evaporator and up and about the opposite sides thereof in the form of opposed legs 36 that have inwardly directed shoulders 3'7 on their inner sides for engagement over the lateral edges of the body 18, the tops of said legs being connected together and intercommunicating through a fiat tube 38 (see Figs. 3, 4, 9, 10 and 11). At its forward end the [body portion 35 of the tank or receptacle 33 has an upwardly extendingfllip 39 which is downwardly and rearwardly inclined on its inner side to correspond to the angular inclination of the forward end of the evaporator body,

said lip substantially concealing said body from view when the door of the refrigerator is open. Adjacent its rear end, the top wall of the body portion of the tank or receptacle 33 has a depression 40 which accommodates the lower end of the boss 22 of the evaporator body, and when the vessel is slid lengthwise over said body, the rear end of the tank or receptacle strikes the stop 23 to arrest further movement of the vessel, while the lip 39 and the forward wall ofthe depression 40 of the tank are slightly spaced from the adjacent portions of the evaporator body thereby to protect the vitreous enamel or like coating of the tank or receptacle from injury.

The solution 34 that is contained within the tank or receptacle 33 is of a non-eutectic nature and is preferably composed of the following ingredients in, about the proportions mentioned:

Per cent' 'by weight Water 94 Glycerine 4 Tri-sodium phosphate 2 Such a solution we find very satisfactory. Within the possible temperature range of the apparatus, this solution will not freeze solid, and when it congeals at the lowest temperature of the apparatus it is mushy and might be compared with relatively soft ice cream. When subjected to much lower temperatures the ice formed is not as dense or hard-as waterice, but has about the consistency of well frozen ice cream. A characteristic of the solution is that its freezing point decreases progressively as it congeals. In contradistinction to a eutectic solution, which freezes solid at a given temperature, the noneutectic solution freezes in part as the temperature lowers. As the solution reaches the freezing point of water, a part of the water freezes out, leaving a stronger solution in the interstices between the frozen particles. As the temperature continuesto lower, more water freezes out, leaving a still stronger solution, the frozen particles always being separated by the stronger solution, thus preventing any considerable pressure in any one direction. As tlie process of partial solidification progresses, the solution expands and is displaced upwardly into the vacant portions at the tops of the legs 36 of the tank or receptacle, the air pressure in the opposed legs being equalized through the cross tube 38. The essential purpose of the cross tube is to take care of a possible-situation in which the tank is removed from the evaporator and placed on its side so that the solution would fill the lower leg. (Now considering the structure in the absence of the cross tube 38) the air from; such leg would gradually bubble up through the solution to the upper leg and then when the tank is replaced the liquid would be air bound in the one leg to practically the top thereof. When the liquid would later congeal it might impose such strains upon the adjacent portion of the tank as to cause it to bulge and crack the enamel. Such a situation is avoided by the presence of the tube 38.

The advantages arising from the removability of the tank are ease of cleaning and facility of replacing the tank in case it becomes damaged through any cause without having to disturb any of the parts or joints ofthe refrigeration apparatus or machine.

Having thus described our invention, what we claim is:

1. An evaporator for refrigeration apparatus comprising a distributing head, tubing in looped form communicating therewith and extending therefrom in a substantially horizontal plane, said tubing being solely supported by said head, and a rigid body of metal encasing the tubing and the portion of the heady wherewith it communicates, the same serving as a shelf for the support of an object to be chilled.

2. An evaporator for refrigeration apparatus comprising a distributing head, tubing in looped form communicating therewith and extending therefrom in a substantially horizontal plane, and a shelf-like body of heat conducting material encasing the tubing and having a substantially flat top surface, the underneath surface of said body having ribs within which the convolutions of the tubing are embedded.

3. An evaporator for refrigerationapparatus comprising a distributing head, tubing in looped form communicating with the head and extending therefrom in a substantially horizontal plane, the opposite ends of the loop being connected with said head at different elevations and the tubing being gradually inclined upwardly from the lower to the higher end, and a shelf-like body of heat conducting material encasing the tubing,

the same'havingasubstantially flat top surface and being of variable thickness above said tubing to compensate for the difference in inclination between the latter and said top surface.

4. An evaporator for refrigeration apparatus comprising a distributing head, loops of tubing having one of their ends communicatively connected to said head at one elevation and their opposite ends similarly connected to the head at a higher elevation, the tubing being gradually inclined upwardly from the lower to the higher ends, and a cast metal body encasing the loops and having a substantially fiat top surface, the underneath surface of the body having ribs for the accommodation of the convolutions of the loops.

5. A cooling unit for refrigeration apparatus comprising, in combinatioman evaporator in the nature of a horizontal body serving as a shelf for the support of an object to be chilled, and a receptacle having opposed guiding portions for slidable engagement with the lateral edges of the evaporator, said receptacle containing a cold storage substance and having an open space above the evaporator for' the accommodation of said object.

6. A cooling unit for refrigeration apparatus comprising, in combination, an evaporator in the nature of a horizontally disposed, relatively flat body, and a closed receptacle designed for slidable engagement endwise over the evaporator and having portions extending beneath and up along the opposite sides of the same, the opposite side portions of the receptacle amaterial distance abovethe evaporator being communicatively connected together so as to leave an object receiving space above the evaporator, and a body of cold storage substance within the receptacle.

'7. A cooling unit for refrigeration apparatus comprising, in combination, a substantially horizontal relatively flat shelf-like body having passageways extending therethrough for refrigerant, and a receptacle designed to be slidably engaged endwise over the evaporator, the same extending crosswise beneath the evaporator and up the opposite sides thereof and thence inwardly to provide shoulders that engage over the lateral edges of the evaporator, the receptacle having a lip portion-that practically conceals the evaporator and the evaporator having a stop for limiting the sliding movement of the receptacle with respect to the evaporator.

8. A cooling unit for refrigeration apparatus comprising, in combination, a cup-like member, a metallic body encasing the lower end of said member and containing passageways communicating therewith, the body having a depending boss beneath said member and a stop extending downwardly from the rear thereof, the opposite end of the body having a transverse rib whose forward side is inclined upwardly and forwardly, and

jecting lip for the concealment of the transverse rib of the body, the receptacle being adapted to engage the aforesaid stop to prevent contact between said lip and rib and between the forward side of said depression and the boss, the receptacle being coated with afragile. material and containing a cold storage solution.

9. A cooling unit for refrigeration apparatus comprising, in combination, a cup-like member, a metallic body encasing the lower end of said member and containing passageways communicating therewith, the body having a depending boss beneath said member and a stop extending downwardly from the rear thereof, the opposite end of the body having a transverse rib whose forward side is inclined upwardly and forwardly, and a receptacle for slidable engagement endwise over the body, the same having a horizontal portion for disposition below the body and side portions that extend upwardly along the sides of the body, said side portions being projectedinwardly above the top plane of the body to form shoulders for engagement therewith along the lateral edges of the body, the horizontal portion of the receptacle having a depression for the accommodation of the aforesaid boss and having an upwardly projecting lip for the concealment of the transverse rib of the body, the receptacle being adapted to engage the aforesaid stop to prevent contact between said 11p and rib and between the forward side of said depression and the boss, the receptacle being coated with a fragile material and containing cold storage substance, the top portions of the opposite sides of the receptacle being communicatively connected together above the body.

10. In refrigeration apparatus, the combination of a receiver, an evaporator situated a material distance therebelow, a'tubular connection between the receiver and evaporator, a shell enclosing the receiver and having a boss surrounding the tubular connection, asleeve enclosing and spaced from the tubular connection and interposed between the boss and evaporator, and ins'ulating material filling the shell about said receiver and the space between the sleeve and tubu lar connection.

11. A cooling unit for refrigeration apparatus comprising, in combination, an evaporator, and a closed receptacle for application thereto and that is readily removable therefrom for replacement and cleaning purposes, the same being coated with fragile material and containing a non-eutectic solution that will partially congeal at temperatures attained during the operation of the apparatus.

12. A cooling unit for refrigeration apparatus comprising, in combination, an evaporator, and a closed receptacle for application thereto, the same being coated with fragile material and containing a solution of water, glycerine and trisodium phosphate.

13. A cooling unit for refrigeration apparatus comprising, in combination, an evaporator, and a closed receptacle for application thereto, the same being coated with fragile material and containing a solution of 94% water, 4% glycerine connected together, the receptacle containing a non-eutectic solution to within an appreciable distance of the top thereof.

15. In refrigeration apparatus, the combination of a receiver, arr-evaporator situated a material distance therebelow, a tubular connection between the receiver and evaporator, a shell enclosing the receiver and having an opening for the accommodation of the tubular connection, a sleeve enclosing and spaced from the tubular connection and interposed between the shell and evaporator, and insulating material filling the shell about saidreceiver and the space between the sleeve and tubular connection.

LEE s. CHADWICK. MARC RESEK. THEODORE B. FOCKE. 

